Magneto



A. lu. DAVIS.

Mmm-:1o.

APPLICATION FILED MAR. 8| 192'0. 1,383,605. Patented July 5, 1921.

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' ATTORNEY.

UNITED .i STATES A PATENT orner..

ALFRED U. DAVIS, OF-BALTIMORE, MARYLAND, ASSIGNOR TO DAVIS INSTRUMENT MANUFACTURING- COMPANY, OE BALTIMORE, MARYLAND, A CORPORATION F MARYLAND.

MAGNETQ.

Application filed March 8,

, generators, and more particularly to magwith a cover plate removed.

neto-generators, the object of the invention being toprovide a novel and improved portable machine of this kind, the rotating armature having a manually operated driving means,`and said driving means being also provided with means for periodically closing the electric circuit, sov that 4the current is delivered in a series of impulses.

The object stated is attained by means of a combination and arrangement of parts to bc hereinafter described and claimed, and in order that the same may be better understood, reference is had to the accompanying drawing forming a part of this specification. Y

In the drawing, Figure 1 is an elevation of the device; Fig. 2 1s an enlarged vertical section thereof, and Fig. 3 is a planview Referring specifically to the drawing, 10 denotes a permanent magnet of the usual horseshoe form, between the poles of which the armature 11 is located. The magnet Seats, edgewise, on a base 12 so that the arma-4 ture is positioned to rotate about a vertical axis. The base also Supports a shell 13 which forms a housing inclosing the magnet and other parts associated therewith, and to the top of the shell is fitted a cover 14 having diametrically opposite, outstanding lugs 15 for attachment of a looped strap 16 forming a handle. The device is a portable one, it being of such size and weight that it may be readily carried by means of the strap 16.

The shaft 17 of the armature 11 is supported at its lower end by a bearing stud 18 rising from the base l12 and seating in an aperture in said end of the shaft. The upper end of the armature shaft is supported by a bearing plate 19 seating on the top edge of the magnet 10, and clamped down against the latter by nuts 20 screwed on the upper threaded portions of posts 21 having threaded lower extremities screwed into the Specification of Letters Patent.

Patented July 5, 1921.

1920. Serial No. 354,274.

base 12, from which latter said posts rise and pass through apertures in the plate 19. The posts 21 are continued to the cover 14 and pass through apertures therein, the proi jecting ends taking nuts 22, which latter,

' when theyare screwed down against the lid,

fasten the same in place.

The base 12 and the plate 19 also support a driveshaft 23 to which a coiled spring 24 is connected in such a manner that lit tends to rotate theshaft in one direction. The lower end ofthe shaft 23` is supported by a boss 25 rising from the base 12, and in the under side of the base is an aperture 26 into which the shaft projects, the projectfy ing end of the shaft being tted with a transversepin 27 for the application of a key or other device for turning the shaft, the key being inserted into the aperture 26.

To the upper end of the shaft 23, above the plate 19, is fastened a sector gear 27 which is in mesh with a pinion 28, which latter is integral with, or secured to a ratchet wheel 29. The pinion 28 and its ratchet wheel 29 are loose on a stationary Shaft 30 supported by the base 12 and the plate 19.

On the shaft 30 is also loosely mounted a spur gear 31 which is in mesh with a pinion 32 on the upper end of the armature shaft 17. The gear 31 is fitted with a springpressed pawl 33 which engages the ratchet wheel 29, whereby the motion of the pinion 28 is transmitted to the gear 31, the latter, in turn, transmitting motion to the armature shaft 17 through the pinion 32.

One of the terminals of the magneto-generator is a spring contact plate 34 on which the upper end of the armature shaft 17 bears. The other terminal is so grounded that the circuit is completed when a contact spring 35 on the sector'gear 27 engages the head 36 of a binding post 37 carried by the cover 14, said head being positioned to intercept the contact spring at the end of the rotary movement of the sector gear in one direction. The plate 34is electrically connected to a'second binding ost 38 carried by the cover 14. The two binding posts are insulated from the cover 14 by sheets 39 of suitable insulatingwmaterial. The binding posts rise from the top of the cover, and suitable means are providedV for the attachment of the wires conducting the current to the apparatus utilizing the same. The machine has been designed more particularly for igniting blasting fuses, but it may also be used for various other operations requiring an electric current.

The magneto-generator is operated by turning the shaft 23 in one direction through a key fitted to the lower end thereof, as hereinbefore described. The shaft 23 has an alternating rotary movement, it being turned in one direction by the key, and in the opposite direction by the spring 24. However, by reason of the pawl-and-ratchet connection between the gears 27 and 31, the armature shaft 17 obtains a continuous rotary motion in one direction. The gear 27 oscillates and completes the electric circuit everi time the contact spring 35 engages the head 36, this action taking place at the end of each stroke of said gear in one direction. The current is therefore sent through the line in a series of short 1mpulses. One of the posts 2l Vis in the path of the gear 27 and serves as a stop to limit the amplitude of its oscillations.

I claim:

l. A portable magneto-generator comprising a base; a housing rising from said base;

a magneto within said housing and disposed on said base; a bearing member' on said magneto; a removable cover on said housing; and means for clamping said bearing member and cover against said magneto and housing` respectively, comprising posts rising from said base and passing through said bearing member and cover, and having upper threaded portions, and nuts screwed on said threaded portions and bearing against said bearing member and cover.

2. A portable magneto-generator Comprising a base; a housing rising from said base;

a magneto within said housing and disposed on said base; a bearing member on said magneto; a removable cover on said housing; and means for clamping said 'bearing member and cover against said magneto and housing respectively, comprising posts rising from said base, and having threaded eX- tremities screwed into said base, said posts passing through said bearing member and cover, and having upper threaded portions,

.and nuts screwed on said threaded portions and bearing against said bearing member and cover.

In testimony whereof I aix my signature. ALFRED U. DAVIS. 

